The present disclosure relates generally to subterranean drilling operations and, more particularly, the present disclosure relates to a method and apparatus for solid-liquid separation of drilling fluids for analysis.
Subterranean drilling operations typically utilize drilling fluids to provide hydrostatic pressure to prevent formation fluids from entering into the well bore, to keep the drill bit cool and clean during drilling, to carry out drill cuttings, and to suspend the drill cuttings while drilling is paused and when the drilling assembly is brought in and out of the borehole. For an accurate measurement of oil to water ratio of a drilling fluid, or the solids in a drilling fluid, a mud retort is typically used. A mud retort may evaporate all of the liquid phases of the mud and condense the vapors so that the liquid volumes can be measured from a collector in which an oil phase migrates to the top and a water phase to the bottom.
Mud retorts typically require a series of manual steps to load the drilling fluid, measure the drilling distillate, and reset the retort to be used again. Typical mud retorts also include consumable pieces that must be replaced regularly. For example, the mud retort recommended by the America Petroleum Institute (API) in API RP 13B-2, “Recommended Practice for Field Testing of Oil-based Drilling Fluids,” typically must be manually filled with a drilling fluid sample and a wad of steel wool must be placed at the top of the retort to prevent undistilled portions of the drilling fluid from escaping the retort. Once distilled, the fluid portions of the drilling fluid may be collected and manually measured. An operator must then manually reset the retort by cleaning out the solid portions of the drilling fluid left in the retort, which typically requires a cool-down time, and for the retort to be manually unscrewed to access the non-volatile drilling fluid solids. This process takes time and is not easily automated given the number of steps and the configuration of the API recommended retort. What is needed is an automated retort, which can operate autonomously on a drilling rig and can frequently make retort measurements and report them in near real time, which will allow more accurate control of the drilling mud properties for more efficient drilling.
While embodiments of this disclosure have been depicted and described and are defined by reference to exemplary embodiments of the disclosure, such references do not imply a limitation on the disclosure, and no such limitation is to be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are examples only, and not exhaustive of the scope of the disclosure.